290 WELLCRAFT COASTAL, Twin Verado 250-HP - Moderated Discussion Areas

  ContinuousWave
  Whaler
  Moderated Discussion Areas
  ContinuousWave: Whaler Performance
  290 WELLCRAFT COASTAL, Twin Verado 250-HP

search | FAQ | profile | register | author help

Author Topic:   290 WELLCRAFT COASTAL, Twin Verado 250-HP

glen e posted 12-31-2007 07:30 PM ET (US)
As has been pointed out here a few times, Mercury needs to make [a set of counter rotating REVOLUTION4 propellers in 15-inch pitch] for better thrust to get the Boston Whaler CONQUEST 305 with twin Verado 250-HP out of the water. Today we were were able to take a boat [very similar to the CONQUEST 305] in weight and motors and run REVOLUTION4 17-inch pitch propellers with pretty impresive results. Both the Coastal and 305 are about 8,500-lbs dry. Jim writes:
2006 290 Wellcraft Coastal, 250 Verado's, half-tank of fuel, 20-gallons water, two portly adults, seas calm.
Factory installed MIRAGEplus 15-inch pitch--4,000 RPM, 23.3-NMPH [26.8-MPH], 17.6-GPH
New REVOLTUION4 17-inch pitch-- 4,000-RPM 23.9-NMPH [27.5-MPH], 16.0-GPH
The biggest differences were at idle and at WOT. There's a lot more control at lower RPM like when docking. Wide-open-throttle with the MIRAGEplus 15-inch pitch propellers actually hit the alarm for over revving, and WOT with the REVOLUTION4 was a hair over 6,000-RPM. The surprise of the swap was that the REVOLUTION4 propellers are actually faster at WOT. REVOLUTION4 17-inch pitch propellers at 41.5-NMPH [47.7-MPH] versus the MIRAGEplus 15-inch pitch propeller at 39.0-NMPH [44.8-MPH].
Also, this is a set of those terrible gas guzzler Gen I 250's.
jimh posted 01-01-2008 02:29 PM ET (US)
I've been out on a 305 CONQUEST with twin 250-HP Verado motors, and I guess it must have been set up with the standard MIRAGEplus 15-inch pitch propellers, as this was back in 2004 when the Verado was just introduced, as was the 305 CONQUEST.
What I recall from that ride was the ability of the boat to maintain a slow plane with the motors tucked in. I think the boat would stay on plane at 11 to 12-MPH.
I have also tested (on my own boat) the REVOLUTION4 and MIRAGEplus propellers in 17 and 15-inch pitch, respectively, and I found that they were substantially different in terms of how much engine speed they would allow. My conclusion was that the REVOLUTION4 in 17-inch pitch was a lot more propeller than the MIRAGEplus in 15-inch pitch.
glen e posted 01-01-2008 03:51 PM ET (US)
I think the real answer for current 305 owners is to take Rev 4 17's to a good prop shop and tweak them down to 16 pitch.....or just wait for the rumored V350 at Miami....they will certainly run the 17's...probably 19's....
cooper1958nc posted 01-01-2008 10:44 PM ET (US)
If the speed and fuel measurements are correct, then we can surmise the R4 17s were substantially more efficient as they produced equivalent thrust with less torque (less fuel flow at the same RPM means less throttle, i.e. less manifold pressure, and therefore less torque.)
L H G posted 01-02-2008 06:50 PM ET (US)
I believe the Mercury "Revolution 4" props to be highly efficient in the higher pitches, as Mercury indicates. Probably close to the 80% figure. That has been my experience in testing and running them. They put a lot of your propshaft HP into the water.
I tried a set of Mirage Plus 21's on the Merc 200 EFI's on "Whale Lure" (see Cetacea Page 78), which performed poorly - 5600RPM and 56 MPH. Real top end dogs on my rig, but strong on mid-range cruising at 3500 RPM. The hull is actually too light, with relatively too much power, to properly utilize the Mirage Plus large diameter design.
My 21" Laser II's were giving me, at the same time, same conditions, 6000 RPM and 60 MPH. Mercury says these props run close to 80% efficient in their propeller efficiency data. But they lack blade area for strong, economical, mid-range cruising, and are now considered appropriate for smaller hulls. It is an amazing prop for the lightweight ribside 21 and 18 Outrage, however.
19" Revolution 4's gave me 6300 RPM and 62 MPH, and 21's give 5900 RPM at same speed (these are what I bought). In my case, you can feel the extra performance coming from the TREMENDOUS TOTAL HULL LIFT the two Rev 4's give a relatively light, high powered hull like my 25 Outrage. Above 45 MPH, there is no side spray off the hull, because the boat is riding so high on the "V". In some respects, I almost feel these props are giving too much lift at the expense of hull stability, and I am testing the 23" Tempest Plus props as an alternative.
Rev-4 props also improved the ride of the hull by about 100% over the Laser II's. I credit this to the hull lift of these props. With large vent plugs installed, acceleration is excellent. With solid plugs installed, acceleration was slow.
Tom W Clark posted 01-02-2008 07:22 PM ET (US)
Every boat/motor combination is different so discussing propellers on dissimilar boats may not be of a lot of use, but some of the general observations presented here are worth discussing further.
Based on my experience with the Revolution 4s, I agree they are wonderful propellers for moving heavy, high-horsepower boats like the 305 Conquest. The Rev 4s have a lot of blade area.
Jim's observation that the 17" pitch Revolution 4 is a lot more propeller than the 15" pitch MIRAGEplus is certainly true but is an unfair comparison because of the 2" pitch difference.
The fact is that the 17" Revolution 4 is a lot more propeller than the 17" pitch MIRAGEplus. I have tried both the Revolution 4s and the MIRAGEpluss on my own boat and can tell you there will be about a 250 RPM engine speed reduction when using the same pitch Revolution 4 in place of the MIRAGEplus.
As to "efficiency" we best decide how to define that phrase. On my Revenge 25 with twin 150 HP Mercury outboards I have tried the Revolution 4s in the 17" and 19" pitches, the MIRAGEpluss in the 17" and 19" pitches and the Laser II in the 21" pitch as well as numerous other propellers.
While the Laser II was the second fastest propeller for top speed, it was all-around a lousy prop for the 25 foot Whaler. The 17" Revolution 4s are not enough pitch and the 19" are too much being sluggish in acceleration and not as fast as the 19" MIRAGEpluss which continue to provide me with the best performance on my 25 foot Whaler. They are just excellent props for that boat yielding the best fuel economy at cruise speed of any of the the numerous props I have tested including both pitches of the Rev 4s. For me, the MIRAGEplus is the "most efficient".
I agree with Glen that the Verado equipped 305 Conquest would benefit form a 15" or 16" version of the counter rotating Revolution 4. His idea of reducing pitch on a pair of 17" Rev 4s is a pretty good one. I would like to sell my pair of 17" Revolution 4s if anybody with a 305 Conquest is interested in taking that path.
L H G posted 01-02-2008 08:42 PM ET (US)
Mercury has had plenty of time to produce a lefty Rev 4 in 15" pitch. But they haven't.
My guess is they only offered the 15" version, and at a later date, because they had to, to accomodate single engine installations offering minimum acceptable HP for a given boat. I don't think Mercury want their builders and dealers to be rigging boats this way, as underpowering usually results in a dissatisfied customer, running a lower efficiency prop.
Generally, Mercury only makes their performance lines of propellers in 17" or 19" and higher pitches, probably because of the efficiency factor, and in the lower (slower) pitches, performance props are not needed and do little over a Vengeance (a surprisingly good propeller). Only the elephant ear alums and Vengeance props are offered in lower pitches, along with the semi-elephant ear Mirages (which remember were designed for Sterndrive big block applications).
So don't hold your breath waiting for a lefty 15" Rev 4. Instead, buy more HP and it won't be needed.
Peter posted 01-02-2008 09:31 PM ET (US)
Like Tom, I also saw about a 250 RPM reduction going from a pair of 17 inch Mirage Pluses to a pair of 17 inch Revolution 4s on the 27 Whaler WD. The Mirage Plus propellers were more efficient at cruising speeds in flat water as indicated by the MPG readout of the Navman 3100 fuel computer and had a higher top speed (about 2 MPH) than the Rev 4s but they produced an uncomfortable ride in heavy chop. The best way to describe it is that they simply would not stay "hooked up" well enough to power the boat through the chop and this was also indicated by a comparatively poor MPG readout of the Navman when in a chop.
In contrast, the Rev 4s don't blow out and being a 4 blade propeller they provide far superior docking control. They also allow the 27 Whaler WD to plane at a lower speed and I don't need to throttle up carefully when getting on plane like I had to with the Mirages.
In both cases, I ran with the vents plugged up.
While more HP could be a solution, the problem with the Conquest 305 is that Whaler doesn't offer the boat with more HP than a pair of Verado 250s. So, based on Whaler's performance report, that means that Conquest 305 owners are stuck with propellers in the 15 inch or less pitch range.
handn posted 01-03-2008 09:34 PM ET (US)
I have a 305 Conquest with Yamaha-made Mercury 225-HP EFI four-cycle motors and Revolution4 17-inch pitch propellers. I think the propellers match the characteristics of the boat almost perfectly. Without use of trim tabs, the boat will hold a plane at a little over 10-NMPH [11.5-MPH] in nasty slop and that is a lot better than mushing along at displacement speeds. I ran a Mirage on my 23 Conquest single. The boat wouldn't hold a plane below 18-NMPH [20.7-MPH] and often this was uncomfortably fast for conditions. I am running about 5,600-RPM at wide open throttle. The boat is loaded with water, tools, lures, dishes, and so on. Perhaps it would turn close to 6,000-RPM empty, a quarter full of gas without my big butt sitting in the helm chair.
My guess is that twin 250-HP Verado motors will turn at more than 5,600-RPM with the 17-inch-pitch Revolution4 propellers at WOT, although perhaps less than 6,000-RPM.
My question to Verado gurus is what is the problem with this? With other engines it is acceptable if the engines run in the middle of the range and don't need to run at maximum RPM. Would running at a lower RPM damage the supercharged Verado? Perhaps I haven't found the right shop yet, but I have had bad luck with prop shops messing with my stainless steel props. There are aftermarket four-blade propellers; perhaps one of these matches the needs of the Verado better than the Revolution4.

Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.

Author	Topic: 290 WELLCRAFT COASTAL, Twin Verado 250-HP
glen e	posted 12-31-2007 07:30 PM ET (US) As has been pointed out here a few times, Mercury needs to make [a set of counter rotating REVOLUTION4 propellers in 15-inch pitch] for better thrust to get the Boston Whaler CONQUEST 305 with twin Verado 250-HP out of the water. Today we were were able to take a boat [very similar to the CONQUEST 305] in weight and motors and run REVOLUTION4 17-inch pitch propellers with pretty impresive results. Both the Coastal and 305 are about 8,500-lbs dry. Jim writes: 2006 290 Wellcraft Coastal, 250 Verado's, half-tank of fuel, 20-gallons water, two portly adults, seas calm. Factory installed MIRAGEplus 15-inch pitch--4,000 RPM, 23.3-NMPH [26.8-MPH], 17.6-GPH New REVOLTUION4 17-inch pitch-- 4,000-RPM 23.9-NMPH [27.5-MPH], 16.0-GPH The biggest differences were at idle and at WOT. There's a lot more control at lower RPM like when docking. Wide-open-throttle with the MIRAGEplus 15-inch pitch propellers actually hit the alarm for over revving, and WOT with the REVOLUTION4 was a hair over 6,000-RPM. The surprise of the swap was that the REVOLUTION4 propellers are actually faster at WOT. REVOLUTION4 17-inch pitch propellers at 41.5-NMPH [47.7-MPH] versus the MIRAGEplus 15-inch pitch propeller at 39.0-NMPH [44.8-MPH]. Also, this is a set of those terrible gas guzzler Gen I 250's.
jimh	posted 01-01-2008 02:29 PM ET (US) I've been out on a 305 CONQUEST with twin 250-HP Verado motors, and I guess it must have been set up with the standard MIRAGEplus 15-inch pitch propellers, as this was back in 2004 when the Verado was just introduced, as was the 305 CONQUEST. What I recall from that ride was the ability of the boat to maintain a slow plane with the motors tucked in. I think the boat would stay on plane at 11 to 12-MPH. I have also tested (on my own boat) the REVOLUTION4 and MIRAGEplus propellers in 17 and 15-inch pitch, respectively, and I found that they were substantially different in terms of how much engine speed they would allow. My conclusion was that the REVOLUTION4 in 17-inch pitch was a lot more propeller than the MIRAGEplus in 15-inch pitch.
glen e	posted 01-01-2008 03:51 PM ET (US) I think the real answer for current 305 owners is to take Rev 4 17's to a good prop shop and tweak them down to 16 pitch.....or just wait for the rumored V350 at Miami....they will certainly run the 17's...probably 19's....
cooper1958nc	posted 01-01-2008 10:44 PM ET (US) If the speed and fuel measurements are correct, then we can surmise the R4 17s were substantially more efficient as they produced equivalent thrust with less torque (less fuel flow at the same RPM means less throttle, i.e. less manifold pressure, and therefore less torque.)
L H G	posted 01-02-2008 06:50 PM ET (US) I believe the Mercury "Revolution 4" props to be highly efficient in the higher pitches, as Mercury indicates. Probably close to the 80% figure. That has been my experience in testing and running them. They put a lot of your propshaft HP into the water. I tried a set of Mirage Plus 21's on the Merc 200 EFI's on "Whale Lure" (see Cetacea Page 78), which performed poorly - 5600RPM and 56 MPH. Real top end dogs on my rig, but strong on mid-range cruising at 3500 RPM. The hull is actually too light, with relatively too much power, to properly utilize the Mirage Plus large diameter design. My 21" Laser II's were giving me, at the same time, same conditions, 6000 RPM and 60 MPH. Mercury says these props run close to 80% efficient in their propeller efficiency data. But they lack blade area for strong, economical, mid-range cruising, and are now considered appropriate for smaller hulls. It is an amazing prop for the lightweight ribside 21 and 18 Outrage, however. 19" Revolution 4's gave me 6300 RPM and 62 MPH, and 21's give 5900 RPM at same speed (these are what I bought). In my case, you can feel the extra performance coming from the TREMENDOUS TOTAL HULL LIFT the two Rev 4's give a relatively light, high powered hull like my 25 Outrage. Above 45 MPH, there is no side spray off the hull, because the boat is riding so high on the "V". In some respects, I almost feel these props are giving too much lift at the expense of hull stability, and I am testing the 23" Tempest Plus props as an alternative. Rev-4 props also improved the ride of the hull by about 100% over the Laser II's. I credit this to the hull lift of these props. With large vent plugs installed, acceleration is excellent. With solid plugs installed, acceleration was slow.
Tom W Clark	posted 01-02-2008 07:22 PM ET (US) Every boat/motor combination is different so discussing propellers on dissimilar boats may not be of a lot of use, but some of the general observations presented here are worth discussing further. Based on my experience with the Revolution 4s, I agree they are wonderful propellers for moving heavy, high-horsepower boats like the 305 Conquest. The Rev 4s have a lot of blade area. Jim's observation that the 17" pitch Revolution 4 is a lot more propeller than the 15" pitch MIRAGEplus is certainly true but is an unfair comparison because of the 2" pitch difference. The fact is that the 17" Revolution 4 is a lot more propeller than the 17" pitch MIRAGEplus. I have tried both the Revolution 4s and the MIRAGEpluss on my own boat and can tell you there will be about a 250 RPM engine speed reduction when using the same pitch Revolution 4 in place of the MIRAGEplus. As to "efficiency" we best decide how to define that phrase. On my Revenge 25 with twin 150 HP Mercury outboards I have tried the Revolution 4s in the 17" and 19" pitches, the MIRAGEpluss in the 17" and 19" pitches and the Laser II in the 21" pitch as well as numerous other propellers. While the Laser II was the second fastest propeller for top speed, it was all-around a lousy prop for the 25 foot Whaler. The 17" Revolution 4s are not enough pitch and the 19" are too much being sluggish in acceleration and not as fast as the 19" MIRAGEpluss which continue to provide me with the best performance on my 25 foot Whaler. They are just excellent props for that boat yielding the best fuel economy at cruise speed of any of the the numerous props I have tested including both pitches of the Rev 4s. For me, the MIRAGEplus is the "most efficient". I agree with Glen that the Verado equipped 305 Conquest would benefit form a 15" or 16" version of the counter rotating Revolution 4. His idea of reducing pitch on a pair of 17" Rev 4s is a pretty good one. I would like to sell my pair of 17" Revolution 4s if anybody with a 305 Conquest is interested in taking that path.
L H G	posted 01-02-2008 08:42 PM ET (US) Mercury has had plenty of time to produce a lefty Rev 4 in 15" pitch. But they haven't. My guess is they only offered the 15" version, and at a later date, because they had to, to accomodate single engine installations offering minimum acceptable HP for a given boat. I don't think Mercury want their builders and dealers to be rigging boats this way, as underpowering usually results in a dissatisfied customer, running a lower efficiency prop. Generally, Mercury only makes their performance lines of propellers in 17" or 19" and higher pitches, probably because of the efficiency factor, and in the lower (slower) pitches, performance props are not needed and do little over a Vengeance (a surprisingly good propeller). Only the elephant ear alums and Vengeance props are offered in lower pitches, along with the semi-elephant ear Mirages (which remember were designed for Sterndrive big block applications). So don't hold your breath waiting for a lefty 15" Rev 4. Instead, buy more HP and it won't be needed.
Peter	posted 01-02-2008 09:31 PM ET (US) Like Tom, I also saw about a 250 RPM reduction going from a pair of 17 inch Mirage Pluses to a pair of 17 inch Revolution 4s on the 27 Whaler WD. The Mirage Plus propellers were more efficient at cruising speeds in flat water as indicated by the MPG readout of the Navman 3100 fuel computer and had a higher top speed (about 2 MPH) than the Rev 4s but they produced an uncomfortable ride in heavy chop. The best way to describe it is that they simply would not stay "hooked up" well enough to power the boat through the chop and this was also indicated by a comparatively poor MPG readout of the Navman when in a chop. In contrast, the Rev 4s don't blow out and being a 4 blade propeller they provide far superior docking control. They also allow the 27 Whaler WD to plane at a lower speed and I don't need to throttle up carefully when getting on plane like I had to with the Mirages. In both cases, I ran with the vents plugged up. While more HP could be a solution, the problem with the Conquest 305 is that Whaler doesn't offer the boat with more HP than a pair of Verado 250s. So, based on Whaler's performance report, that means that Conquest 305 owners are stuck with propellers in the 15 inch or less pitch range.
handn	posted 01-03-2008 09:34 PM ET (US) I have a 305 Conquest with Yamaha-made Mercury 225-HP EFI four-cycle motors and Revolution4 17-inch pitch propellers. I think the propellers match the characteristics of the boat almost perfectly. Without use of trim tabs, the boat will hold a plane at a little over 10-NMPH [11.5-MPH] in nasty slop and that is a lot better than mushing along at displacement speeds. I ran a Mirage on my 23 Conquest single. The boat wouldn't hold a plane below 18-NMPH [20.7-MPH] and often this was uncomfortably fast for conditions. I am running about 5,600-RPM at wide open throttle. The boat is loaded with water, tools, lures, dishes, and so on. Perhaps it would turn close to 6,000-RPM empty, a quarter full of gas without my big butt sitting in the helm chair. My guess is that twin 250-HP Verado motors will turn at more than 5,600-RPM with the 17-inch-pitch Revolution4 propellers at WOT, although perhaps less than 6,000-RPM. My question to Verado gurus is what is the problem with this? With other engines it is acceptable if the engines run in the middle of the range and don't need to run at maximum RPM. Would running at a lower RPM damage the supercharged Verado? Perhaps I haven't found the right shop yet, but I have had bad luck with prop shops messing with my stainless steel props. There are aftermarket four-blade propellers; perhaps one of these matches the needs of the Verado better than the Revolution4.